Every art museum needs a frame, and the Berkeley Art Museum and Pacific Film Archive celebrated a milestone Thursday in the construction of its future home — the placement of the last steel beam in the new building’s structural frame — with a New Orleans-flavored block party and “topping out” ceremony on Addison Street.

BAM/PFA director Lawrence Rinder: block party now, parade later.

The tradition, explained John Wilson, president of the company that’s erecting the museum’s new home, Plant Construction, started with iron workers, whose job was done once the final beam was set in place. “So they’d grab an apprentice, send him out for a case of beer, and then they’d all gather together, sitting on the tailgate of a pickup truck, and say, ‘Look what a great job we did, we’ll let the rest of these guys finish this.'”

In the last light of an overcast Thursday, that tradition was extended to include Berkeley residents, members of the campus community and art and film lovers — often the same people — who got an opportunity to sign the final beam with felt-tipped markers, aided by the New Orleans-style accompaniment of the 14-piece brass band Mission Delirium and vendors of wine, beer and artisanal snow cones. The crowd had dwindled a bit by 7 p.m., but was still in a party mood when an overhead crane carried the colorfully tagged beam from the street to the top of the new structure.

Among those signing the final beam was Wendy Cohen (in blue), advertising director for Berkeleyside, the event’s media sponsor.

In addition to Wilson, UC Berkeley Vice Chancellor John Wilton, Berkeley Vice Mayor Linda Maio and Lawrence Rinder, BAM/PFA’s director, took the microphone briefly to commemorate the midpoint in construction of the relocated museum, which integrates the campus’s long-shuttered printing plant at Center and Oxford with a new structure extending north to Addison. The foundation for the complex, said Wilson, is “literally sitting in Strawberry Creek, so we’ve built a boat for a foundation.”

When the complex finally replaces the current, seismically unsound museum in January 2016, Rinder said, it will feature a number of advantages, including twice the space for education and collection access, so that “the material richness of UC Berkeley’s collection will be accessible to a broader public.” It will also include two theaters, allowing simultaneous PFA programs in spaces designed specifically for films “for the first time in our history.”

Construction workers prepare the beam for liftoff.

“You will be able to see films here,” he promised, “better than you can see them anywhere in the world.”

Rinder said construction of the new museum complex — designed by the architectural firm Diller Scofidio + Renfro, responsible for New York City’s High Line and the Boston Institute of Contemporary Art — would be finished a year from now, but that it could take an additional six months before exhibitions were ready for public viewing. A “naked opening” of the completed structure, sans art, is planned for next fall.

Meanwhile, Rinder made clear he was looking forward to “getting the keys” to the new building in July 2015.

“My staff will have a parade down the street,” he joked to the crowd, “and you can help us carry the Rothko.”